U.S. Pat. No. 4,297,488 discloses different processes for the preparation of cefoxitin, which uses ester protected cephem nucleus. These processes involve deprotection after carbamoylation because of which, yield of the product is less.
U.S. Pat. Nos. 4,210,750 and 4,292,750 disclose a process for the preparation cefoxitin, which involve the usage of an isocyanate wherein the labile substituent is hydrocarbyl or substituted hydrocarbyl group.
The above said prior art processes always yield cefoxitin with poor quality, and color.
We have now found an improved process for the preparation of the compound of formula (I), which process has advantages over the processes described in the above-mentioned prior art documents.